﻿/*****
 *  Copyright 2011, Kaven Gagné
 *
 *  Licensed under the Apache License, Version 2.0 (the "License");
 *  you may not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 *
 *  http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 */

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace Knowledge
{
    public class GenStack<T>
    {
        T[] items;
        int size;
        int stackPtr;

        public GenStack():this(100){}
        public GenStack(int Size)
        {
            size = Size;
            items = new T[Size];
            stackPtr = 0;
        }

        public void push(T item)
        {
            if (stackPtr >= size)
                throw new StackOverflowException();
            items[stackPtr] = item;
            stackPtr++;
        }

        public T pop()
        {
            stackPtr--;
            if (stackPtr >= 0)
            {
                return items[stackPtr];
            }
            else
            {
                stackPtr = 0;
                throw new InvalidOperationException();
            }
        }
    }
}
